Community Forums

HUGHVER · 06-03-2011, 07:29 AM

Both the black and grey holding tank level indicators always read 3/4 full, even just after I drain them. I purchased this coach just over a year ago and I suspect that it had not been used for a year or so before my acquisition. Is there some way to correct this problem without replacing the sensors? Thanks for the help.

450Donn · 06-03-2011, 07:35 AM

Look up geo method of cleaning the tanks. The gages are notorious for being inaccurate, but there are things you can do to help them work better. Start off by dumping Calgon water softener into each holding tank and filling them with water. You can also add a 10# bag of crushed ice to the black tank and go for a drive. The sloshing around of the ice and calgon/water mix will help clean the tanks and sensors.

wa8yxm · 06-03-2011, 08:28 AM

Very normal.. The Geo Method has worked on occasion. Another thing that works fairly well.. Again on occasion, is a tank rinsing wand, Specifically my home made version of the Valterra Master blaster.. NOTE, most wants are about as effective as holding a garden hose over the toilet.. (not much) this one actually BLASTS the sensors clean if you aim it right.

I have also tried teh RV-Twister wand from Camco.. Heard good things, looked good "on paper" as it were, was not all that impressed with the performance, Will continue my tests.

Sensor Cleaner products, (TST with Sensor Cleaner, Thetford Sensor Cleaner) are a joke.. I compared the regular stuff with the "With senssor cleaneer" they added salt, common table salt. That ought to rust them not clean them

Want sensors that work,, Google: See Level RV

njs42 · 06-03-2011, 09:24 AM

Mine work great after nine years.

First; do your sensors read from inside the tank?---some have a strip on the outside etc; so cleaning (even though you should anyway) will not necessarily solve the problem. If they are inside regular cleaning is easy and can be done on the road. Look at some past threads on this subject and you will find plenty of different opinions about the best substance to put in the tank. Dawn dish soap, etc: RV supplies have tank cleaner but it is pricey.

Basically fill the tank 3/4 with whatever you want to clean it with and drive---warmer the day the better. Then dump the tank and rinse. If it does not work the first time then do it again.

My black tank sensors can be cleaned pronto by putting a wand down the toilet and spraying---work great and instantly. Grey tank takes the above proceedure.

If your sensors are exterior then the problem may be in the sensor itself---but I imagine/guess a build up of crud could give a false reading---so clean the tanks and you should be happy.

Clay L · 06-03-2011, 09:30 AM

The problem is not the sensors, it is crudded up tank walls. The crud holds moisture and fools the sensors. Anything that cleans the tanks walls will help.

I have tried just about all of the proposed remedies including the urban myth types like ice cubes in the black tank and so far have found nothing that works. If you have a black tank flusher system that will help a lot if you use it religiously.

Very few RVs have flusher systems in the gray tank so it would be nice to have a solution for that tank but I haven't found one yet.

ImagineIF · 06-03-2011, 10:22 AM

I have the same problem with the black water tank. If I use the built in sprayer when emptyng the tank the meter will read empty. Then after a couple uses it's back to 3/4 full reading. I suspect, as mentioned earlier, stuff gets on the side of the tanks leading to false readings.

BTW, the ice in the black water tank is not urban legend. It's common practice in boats to break up sludge. Unlike an RV, the boat tank is empty by sucking the it empty not from a drain on the bottom of the tank.

chiefdave · 06-04-2011, 09:24 PM

I had the same problem for a number of years. I installed a 4" deck plates on my black and grey water tanks. I use a normal garden hose with a spray nozzle to flush the tanks about every third use. Have never had a problem after installing the deck plates. Got the mod idea from Drifter at quartsite 2011. Make sure you get the deck plate with the seal in the top.

offthewall · 06-04-2011, 09:48 PM

Quote:

Originally Posted by chiefdave

I had the same problem for a number of years. I installed a 4" deck plates on my black and grey water tanks. I use a normal garden hose with a spray nozzle to flush the tanks about every third use. Have never had a problem after installing the deck plates. Got the mod idea from Drifter at quartsite 2011. Make sure you get the deck plate with the seal in the top.

Just curious, what are 4" deck plates?

M&EM · 06-04-2011, 10:11 PM

Quote:

Originally Posted by wa8yxm

Very normal.. -----
Want sensors that work,, Google: See Level RV

I've used See level for the past 5 years and found them trouble free for the most part. Tank shape and height may be issues with them. I have some of those issues. Accumulations on the inside walls can also affect the See level as the sensor tends to detect the excess liquid in the accumulated waste. I have found limited success using water softeners added to the waste water which makes the water wetter and loosens stuck wall crud.

Marty

Pairajays · 06-04-2011, 11:19 PM

Level indicators for holding tanks sounds like a must have. That is not necessarily true. OEM systems are notorious for poor performance. I finally gave up on my systems and just keep a close watch. When your shower water want drain, you know your tank is full. The black tank is a little different. I have learned to tell by sound, when you flush, if the tank needs dumping. If you boondock s lot, this would not work to good.

Jim E

NITEHAWK · 06-05-2011, 07:36 AM

Just wondering, as I have never seen any mention of this, but why not fill the black water tank about half full, add a can of Drano then drive around for awhile?
Tank is plastic, dump valve is plastic, seals are rubber, everything same as house plumbing so why not??

Gary RVRoamer · 06-05-2011, 09:01 AM

The basic problem is crud on the sidewalls, as Clay L. described. Besides using my tank flush regularly, about once a year I fill the waste tanks and add an enzyme-based septic degreaser/cleaner such as Roebic 57 or Roebic 67. Let it sit for 72 hours or so and the enzyme critters generally eat the sidewalls clean.

If you have sensors that mount through the walls of the tank (thecommon type), I recommend switching to See Level external sensors from Garnet. They are far less sensitive to accumulated crud on the tank walls.

SeeLeveL Liquid Level Gauges by Garnet Instruments Ltd.